Microbial fuel cells generating electricity from rhizodeposits of rice plants.

Living plants transport substantial amounts of organic material into the soil. This process, called rhizodeposition, provides the substrate for the rhizospheric microbial community. In this study, a laboratory-scale sediment microbial fuel cell, of which the anode is positioned in the rhizosphere of the rice plants, is used to microbially oxidize the plant-derived organics. An electrical current was generated through the in situ oxidation of rhizodeposits from living rice plants. The electrical power output of a sediment microbial fuel cell was found to be a factor 7 higher in the presence of actively growing plants. This process offers the potential of light-driven power generation from living plants in a nondestructive way. Sustainable power productions up to 330 W ha(-1) could be attributed to the oxidation of the plant-derived compounds.